In general, a cellular wireless communication system divides the entire coverage into a plurality of cells and covers the cells through Node Bs or Base Stations (BSs), respectively, such that it supports uninterrupted continuous communication of Mobile Stations (MSs) or User Equipment (UE), moving between cells.
The BS includes a modem that performs a digital communication processing and a Radio Frequency (RF) unit that performs an RF signal processing. The BS performs traffic processing requested by a plurality of MSs placed in a cell. The traffic processing is completed through an available Resource Block (RB) in the BS. That is, one or more RBs are allocated to a cell which is covered by the BS or to each sector which is included in the cell, and a separate transmission/reception path is normally required for each RB.
Meanwhile, according to the increase in demand for a high capacity data service such as a variety of multimedia internet services, as well as a voice call in a wireless communication market, a variety of wireless transmission technologies have been developed in order to satisfy the demand. Research on MIMO technology, which is one of the wireless transmission technologies, is currently an attractive field. Because the MIMO system uses multiple antennas at its transmission/reception port, respectively, the MIMO system may increase a channel transmitting capacity in proportion to the number of antennas without an additional allocation of transmission power or frequency, in comparison with a system that utilizes a single antenna.
The MIMO technology uses a plurality of transmission/reception antennas such that it additionally utilizes a transmission/reception path that corresponds to each of the transmission/reception antennas, thereby largely increasing power consumption of the BS.
Recently, as the interest in the environment and energy efficiency has increased, the demand for not only the MS using a battery with a limited capacity but a variety of technologies for reducing unnecessary power consumption in the BS has increased. Accordingly, the technology for preventing the use of unnecessary power and reducing power consumption in the BS of the wireless communication system is required.